Codes 84 and 99

[94GMC2500]

I have 84 and 99 codes on my 95 k3500. Is this a indication the APP is bad or something else?

Some times the pedal feels like it has a dead spot in it.

[Warren96]

Did you swap the PMD yet? Are these the only codes set?

[94GMC2500]

Only 84 and 99 codes, new pmd about a year ago.

[94GMC2500]

Is there a way to test the accelerator pedal position sensor?

[DmaxMaverick]

Is there a way to test the accelerator pedal position sensor?

Yes, and your truck's PCM already did. All you can do is check the connections and/or replace the module. The APP has 3 independent/redundant circuits. If one fails (or if all 3 don't agree), it warns you, and the SES and STS (Service Throttle Soon) lamps should be on. If 2 fail, it limps. If 3 fail, it doesn't work.

[94GMC2500]

Thanks for the info!